Formation of cumulus humilis clouds mostly over the sea areas with little vertical extent due to thermal boundary at a height of 740 metres. In fact, as expected for cumulus humilis, the photographed clouds are small and flattened. Furthermore, these correspond perfectly with the visible satellite image taken at the time which show Cu humilis in great abundance over the waters of the Central Mediterranean region whilst dissipated over land due to being evaporated by the heat of the sun when cut off from their moisture source. The first thumbnail is the weather sounding that produced these clouds with ‘Thermal’ due to cooler air travelling over a still warm sea with the higher pressure towards our west producing a Mistral current as per third thumbnail. Cirrus clouds were observed at the time and it was mainly due to moist upper-level airmass rather than indicating a weather feature.